The invention relates to a connector for optical waveguides, with a connector housing at whose one end a fiber optic cable is inserted and at whose opposite end ferrules exit, which are each encapsulated in an inner ferrule individual housing which, on the outsides of the housing, has locking means, each of which interacts with a locking counter-element of a connector counter-coupling, whereby the inner ferrule individual housings are each held in an outer ferrule individual housing and are movable in the axial direction with respect thereto, said outer ferrule individual housing being accommodated in the connector housing such that it is movement-coupled and has means with which the lock between the inner ferrule individual housing and the locking counter-element of the connector counter-coupling can be released by axially moving the outer ferrule individual housing with respect to the inner ferrule individual housing in the direction of the cable insertion end, according to the generic part of claim 1.
Connectors of the type described above offer better protection again inadvertent unplugging of the connector through improper handling. However, it has been found that the release mechanism can also be released by pulling firmly on the fiber optic cable itself. Due to the frictional or non-positive connection between the connector housing, the cable and the outer ferrule individual housing, such pulling causes a relative movement between the outer ferrule individual housing and the counter-coupling.
The invention is based on the objective of creating a connector of the above-mentioned type with a reliable unplugging protection means, which cannot be inadvertently unplugged by pulling on the cable.
This objective is achieved according to the invention with a connector of the above-mentioned technical area in that, between the fiber optic cable and the inner ferrule individual housing, there is a movement-coupled connection that can be moved with respect to the connector housing.
The movement coupling can preferably be effectuated by positive connection measures as well as by frictional connection measures, e.g. by a movement coupler.
In a preferred embodiment of the invention, the movement coupling between the fiber optic cable and the inner ferrule individual housing is created by an indirect positive connection in that, for example, the connector housing accommodates an inner core housing in which the fiber optic cable, on the one hand, and the ferrules, on the other hand, are held in a form-fitting manner, said core housing being arranged in the connector housing so as to be movable in the axial direction. Therefore, between the fiber optic cable and the inner ferrule individual housing, advantageously a movement-coupled connection is formed with respect to the connector housing.
According to the invention, a tensile force that acts on the fiber optic cable is transmitted via the connection, which is movable with respect to the connector housing, to the inner ferrule individual housing and only from there to the outer ferrule individual housing. Thus, the tensile force acting on the fiber optic cable does not move the outer ferrule individual housing relative to the inner ferrule individual housing towards the connector housing, so that the lock between the outer ferrule individual housing and the counter-coupling is not released.
In this manner, it is ensured that, if the fiber optic cable is pulled, the movement sequence of the connector parts is defined in such a way that the release mechanism between the outer ferrule individual housing and the locking elements of the connector counter-coupling cannot go into action. Therefore, according to the invention, the connector can only be released from the counter-coupling by pulling on the connector housing. In contrast, when the cable is pulled, assuming normal tensile forces, the connector remains locked and cannot be released by the counter-coupling since the triggering mechanism is not activated by pulling on the cable.
This characteristic is enhanced by the fact that the movement path in the outer ferrule individual housing for the inner ferrule individual housing that is accommodated so as to be axially movable therein is the same as or smaller than the movement path in the connector housing for the core housing that is accommodated therein and that is axially movable therein.
Advantageously, in one embodiment, the inner core housing is divided into chambers which, in an at least partially form-fitting manner, accommodate, for example, a cable crimping sleeve with a collar that is mounted on the fiber optic cable and the ferrules. Here, the depth of the chamber that accommodates the collar is dimensioned in such a way that the cable crimping sleeve is movement-coupled with the chamber without time delay or path delay, that is to say, it is positively connected to the inner core housing without slippage. The tensile force is essentially introduced via this positive fit, whereby, depending on the embodiment, other accommodation sites for the cable parts can contribute to the force transmission.
Additional force can be introduced, for example, using another chamber that is delineated by a partition on one side and by a rear wall on the other side, and that accommodates a collar of a cable anti-kink means applied on the fiber optic cable. In order to create appropriate shoulders and projections with which a movement limitation for the core housing can be achieved, in one embodiment, the chambers are arranged one after the other in a step-like manner.
The partitions and dividing walls located between the chambers inside the inner core housing are advantageously provided with passage openings. In another embodiment, individual fibers that exit from the end of the fiber optic cable inserted into the connector extend through a chamber of the core housing, with their free ends each connected to a ferrule and bordered by a crimping ring that has a collar on each chamber side and that grasps behind the coupling-side end wall of the chamber. For this purpose, the chamber end wall has ferrule outlet openings whose cross section is dimensioned smaller than the collar of the corresponding ferrule crimping ring. The ferrules themselves are encapsulated in the inner ferrule individual housing so as to be axially unmovable.
This creates the positive connection between the fiber optic cable, the inner core housing, the inner ferrule individual housing and the ferrules.
The inner core housing is accommodated so as to be axially movable in the connector housing, whereby the axial direction designation refers to a linear movement parallel to the axis of the connector extending from the cable insertion end to the ferrule outlet side.
The connector housing in a preferred embodiment has a shaft into which the core housing is inserted. The shaft is dimensioned in such a way that the core housing can be moved inside the connector housing in the axial direction, whereby the shaft is dimensioned in such a way that its inner walls that extend crosswise to the axis direction function as a stop for the axial movement of the core housing inside the connector housing.
Moreover, in a preferred embodiment, the coupling-side end of the connector housing has a double shaft in which two adjacently arranged ferrules are accommodated. The outer ferrule individual housings are movement-coupled with the connector housing, whereby a positive connection is most advantageous.
In a preferred embodiment of the invention, a cap can be placed as a protective sleeve over the connector housing in order to protect the connector housing from being accessed and from being unplugged from the counter-coupling. The cap is provided with retention means that can be clipped or hooked to the inner core housing, so that the cap follows the movement of the core housing. Additional advantageous embodiments of the invention are described in the subordinate claims. The cap can only be removed by means of an unlocking tool.
In a preferred embodiment, the connector housing, the inner core housing and the cap each consist of an upper and lower shell, whereby the upper and the lower shells are each essentially identical.